Sealing device

ABSTRACT

A releasable plug for sealing an open end of a fluid bearing pipe having at its open end an inwardly directed flange formed upon cutting an end of said pipe; said plug including a plug body, an annular recess formed in the body which engages said flange, and sealing means which frictionally engages an inner surface of said pipe thereby providing a pressure seal for said pipe.

BACKGROUND

The present invention relates to pipe sealing devices and moreparticularly, relates to an improved sealing device for the temporarysealing of pipe ends and a method of installation of such device.Although the invention will be described in respect of its applicationto plumbing pipes it will be appreciated by those skilled in the artthat the invention may be applied to piping in other fields.

PRIOR ART

There are numerous devices in the marketplace which are used fortemporary and permanent sealing of fluid bearing pipes. Broadly thesecan be divided into two categories. The first comprises end covers ordust caps which are placed over the ends of pipes to prevent ingress offoreign particles and which have no pressure resistant capabilities. Thesecond category of devices are those which have the capacity to sealpipes bearing pressurised fluids and these generally comprise pneumaticor mechanical devices with the former relying on air pressure to urge aresilient deformable member against the walls or end of a pipe tothereby effect sealing. Another example of sealing devices is a solenoidwherein a plastics material actuated electrically, mechanically engagesthe end of a pipe thereby effecting the seal, even where the pipe bearsa pressurised fluid.

U.S. Pat. No. 3,704,729 for example which falls in the second categoryabove discloses a plumbing device for plugging a pipe including aradially expansible rubber sleeve disposed about an end of an axialshaft or tube. Devices such as this rely on the establishment of africtional engagement between the expansible rubber sleeve and theinternal surface of a pipe to be sealed. However reliance on frictionalengagement has the limitation that resistance to blow out is totallyreliant on the co-efficient of friction established.

An alternative device for closure of a pipe end falling in the firstcategory is disclosed in U.S. Pat. No. 4,046,168. The plug disclosed inthat patent comprises a circular disc portion and an annular skirtprojecting from the periphery of the disc portion to one side thereofand a pipe member which projects in the direction of the longitudinalaxis of the plug from the centre of the disc portion to one side. Thisdevice relies for its engagement and therefore sealing of the pipe on anannular skirt to engage the internal surface of the pipe to be sealedand an abutment member which limits entry of the plug to a predetermineddistance along the pipe. Plugs of this nature rely heavily on frictionalengagement between the material of the plug and the inner surface of thepipe to be sealed and are also prone to popping out where the pressurein the pipe exceeds the capability of the plug to withstand suchpressure even though this is likely to occur at a lower pressurethreshold. Plumbers are frequently engaged in installations whichrequire temporary termination of the water service and restoration ofthe service at the end of the day to prevent interruption to the supplywhere the work temporarily ceases. Where there is partially completedpipe work the pipe ends must be temporarily sealed (sometimes onlyovernight until work recommences the next day) necessitating preparationof a seal that will withstand normal operating pressures.

According to prior art methodology, pipes may be sealed temporarily byfirstly heating the pipe end with Oxy and Acetylene, squeezing orcrimping the heated end closed, followed by brazing the pipe end withsilver solder to ensure a sound joint. Another method was to weld on tothe end of a cut pipe a preformed thread followed by screwing on athreaded cap or valve.

In pipe reticulation networks the tradesman usually leaves testing thepipes until completion due to the time consuming and thus costly methodsof sealing mentioned above. This can result in some networks not beingfully and properly tested due to possible rendering over as buildingwork progresses. If leaks are later detected the builder or tradesmanmust incur the cost of making good the defect. Also, there is a wastagefactor in adopting the crimping and brazing method which adds to thecost of piping. This arises from crimping of the pipe which effectivelydamages a length of pipe which must be later cut off. Plumbers usuallycut off the crimped end to restore the open pipe end which causes lossof anywhere between 100-200 mm of pipe depending upon the distance fromthe crimp the plumber chooses to make the cut.

The present invention seeks to provide a simple alternative to the abovesealing methods and devices, and more particularly provides a removableplug and method of insertion thereof for conveniently sealing a pipewithout complete reliance on friction between the plug and inner wallsof a pipe to be sealed and which precludes the need to temporarily seala fluid bearing pressure pipe by crimping and welding leading to pipewastage.

INVENTION

In one broad form the present invention comprises;

a releasable plug for temporarily sealing an open end of a fluid bearingpipe having at its open end an inwardly directed flange formed uponcutting said pipe; said plug comprising;

an elongated shaft including at a first end a threaded region and at asecond end a collar;

a sleeve surrounding said elongated shaft and including at one end acollett and at a second end an abutment surface wherein sealing meansare provided between said abutment surface and said collar;

and wherein, the sleeve further comprises a recess at or near saidcollett which receives said flange thereby providing resistance againstunwanted release of said plug from said open end of said pipe.

According to a preferred embodiment the sleeve is deformable to allowpassage of the plug through the space defined by said annular flange andto allow said annular flange to engage said recess.

Preferably the threaded region receives a nut which when rotated in afirst direction engages a surface of the collett urging the sleevetowards the collar on said shaft so that said sealing means iscompressed between said sleeve and said collar causing frictionalengagement between the plug and an inner surface of the pipe. Preferablythe sealing means is a rubber O-ring.

In another broad form the present invention comnprises;

a removable plug for temporarily sealing an open end of a fluid bearingpipe or tube including a flange formed at the mouth of said open end andwhich projects radially inwards from an inner surface of said pipe ortube; the plug comprising;

a deformable body having disposed peripherally thereabout a recess orgroove which when said plug is inserted in said opening receives saidflange such that at least one wall of said recess or groove engageseither one or both surfaces of the flange and/or the inner surface ofthe pipe to effect sealing between the plug and pipe.

In its broadest form the present invention comprises;

a releasable plug for sealing an open end of a fluid bearing pipe havingat its open end an inwardly directed flange formed upon cutting an endof said pipe; said plug including a plug body, an annular recess formedin the body which engages said flange, and a seal or a sealing devicewhich frictionally engages an inner surface of said pipe therebyproviding a pressure seal for said pipe.

According to one embodiment the plug comprises a generally disc shapedbody with the recess formed by a bifurcation in the body near thecircumferential region said bifurcation terminating in two resilientlydeformable wall members such that the disc is generally H shaped incross section.

The flange on the pipe or tube is formed preferably by means of a rollercutter which enables the formation of a consistent inwardly directedflange of sufficient strength to withstand fluid pressures which will begenerated on the plug. The flange width may fall within the range 0.1 mmto 3.0 mm.

According to one embodiment in order to effect sealing of the pipe theouter extremity of the wall of the groove upstream of the flange willfrictionally engage the inner surface of the pipe and/or engage theflange. However, unlike the known sealing devices, the plug according tothe invention is not totally reliant on frictional engagement betweenthe body of the plug and the inner wall of the pipe due to theadditional resistance to popping out provided by the engagement betweenthe plug and the flange via a recess in the plug.

Preferably, the walls of the groove are deformable so as to enableconvenient insertion of the plug in the opening of the pipe andparticularly so that either one of the walls (depending upon which waythe plug is inserted) will clear the outer extremity of the flangebefore elastically returning to its original configuration.

According to an alternative embodiment the plug includes a finger orhand grippable element enabling convenient removal of the plug ordisengagement of the seal. The plug is ideally suited for use withcopper or galvanised iron pipes.

According to a method aspect, the present invention comprises;

a method for releasably sealing an end of a pipe comprising the stepsof:

(a) cutting the end of a pipe to be sealed so as to form a flange aboutthe end of the pipe extending radially inwards from an inner surface ofthe pipe;

(b) taking a sealing device as herein described;

(c) inserting the device into an opening in said cut end such that agroove in the device engages said flange thereby sealing the pipe andproviding resistance against unwanted expulsion of said sealing devicefrom said pipe end when said pipe contains a pressurised fluid.

According to the method aspect the invention comprises the further stepof activating a sealing means included on said plug.

DETAILED DESCRIPTION

The present invention will now be described in more detail withreference to the accompanying illustrations wherein:

FIG. 1: shows an isometric exploded view of a plug according to apreferred embodiment of the invention;

FIG. 2: shows a partially assembled isometric view of the plug of FIG.1;

FIG. 3: shows the plug of FIG. 1 fully assembled;

FIG. 4: shows the plug of FIG. 3 fitted to a pipe end with sealing meansactuated;

FIG. 5: shows an isometric view of a plug according to an alternativeembodiment;

FIG. 6: shows an exploded view of the plug of FIG. 5 and pipearrangement;

FIG. 7: shows a long sectional view of the plug of FIG. 5 fullyinstalled in a pipe end;

FIG. 8: shows a long sectional view of the arrangement of FIG. 5 whereinthe plug includes a finger grippable handle;

FIG. 9: shows an alternative embodiment of the invention wherein theplug includes means to enable detachable attachment of a testingapparatus;

FIG. 10: shows a cross sectional elevation of a plug arrangementaccording to an alternative embodiment;

FIG. 11: shows a cross sectional elevation of an alternative plugarrangement including finger grippable handle.

Referring to FIG. 1 there is shown an exploded view of a sealing plug 1according to a preferred embodiment of the invention. The plug isadapted for insertion in the open end of a fluid bearing pipe such asbut not limited to a water pipe. Plug 1 is capable of sealing a pressurepipe and may be used with pipes of various materials such as copper andplastics. The plug is particularly suited for sealing cut ends of pipesin which there is characteristically formed an inwardly directed flangewhich results from the cutting instrument.

Plug 1, according to the preferred embodiment, includes an elongatedshaft 2 having at one end threaded region 3 and at the opposite endcollar 4. Intermediate threaded region 3 and collar 4 resides a taperedregion 5 defining a length from the termination point of thread 3 to arecess 6. Tapered region 5 tapers outwardly from end 5 a to opposite end5 b. Recess 6 defines a longitudinal length from termination 5 b oftapered region 5 to collar 4. Recess 6 receives O ring 7 which, prior toinstallation of the plug, is free to move between bearing surface 8 ofcollar 4 and bearing surface 9 which forms a wall of recess 6. Disposedabout tapered region 5 is an annular floating collar 10 which in usewill engage O ring 7. The internal diameter of floating collar 10 islarger than the largest external diameter along tapered region 5. Plug 1further comprises an annular sleeve 11 comprising collett 12 andelongated shank 13 integrally connected to the collett. Shank 13 has athrough passage 14 which communicates between collett 12 and free end 13a of shank 13. The internal diameter of through passage 14 is greaterthan the widest external diameter of the tapered region 5 whichaccording to the embodiment described occurs at end 5 b. This allowssleeve 11 to float along a longitudinal axis of shaft 2 between O ring 7and annular locking nut 15, which when plug 1 is in use, threadablyengages threaded region 3.

Referring to FIG. 2 there is shown a partially assembled isometric viewof the plug shown in FIG. 1 with nut 15 exploded from threaded region 3of shaft 2. FIG. 2 has been numbered corresponding to FIG. 1. Sleeve 11slides along shaft 2 until it engages floating collar 10 which itselfengages O ring 7. Sleeve 11 can be urged in the direction of collar 4prior to insertion in a pipe to be sealed.

FIG. 3 shows the plug of FIG. 1 fully assembled. In this illustrationlocking nut 15 is engaged with threaded region of shaft 2. Plug 1 ispush inserted into an open end of a pipe to be sealed. In doing so, Oring 7 frictionally engages the inner wall as the O ring is at this timesufficiently loose to allow penetration into the pipe end. Fullinsertion of the plug into the pipe end causes engagement between aflange formed on a pipe end and recess 16 of sleeve 11 which interactionprovides resistance against blowout of the plug once under fluidpressure which will normally be applied axially against collar 4. Theflange is formed when the end of a pipe is cut by a known cuttinginstrument which creates an inwardly directed annular flange which willlocate in recess 16 when plug 1 is fully inserted.

Once plug 1 is fully inserted nut 15 is tightened and as this occursthreaded region 3 of shaft 2 is drawn out causing O ring 7 to besandwiched between collar 4 and floating collar 10. This causesdistortion in O ring 7 and increases the frictional effect between Oring 7 and the inner wall of the pipe. This in conjunction with theengagement of recess 16 with a peripheral flange on the pipe endprovides secure fitting of the plug to the pipe.

Referring to FIG. 4 there is shown a long sectional view through A—A ofthe plug of FIG. 3 inserted in a pipe 17. Pipe 17 includes an inwardlydirected annular flange 18 about pipe end 17 a. Plug 1 is shown fullyinserted into pipe 17 with locking nut 15 tightened to its fullestextent such that O ring 7 is compressed between collar 4 and floatingcollar 10 such that a friction sealing is created between inner wall 17a and O ring 7. In addition, the engagement between the flange 18 andrecess 16 increases the resistance to unwanted blowing out of the plugunder pressure, thereby reducing significantly complete reliance onfriction to ensure proper engagement of plug 1. Whilst each pipe endwill usually be plugged only once each plug may be used repeatedly.

Referring to FIG. 5 there is shown a resiliently deformable plug 20 forinsertion in an opening in a pipe, according to an alternativeembodiment. Plug 20 comprises a generally disc shaped body 21 havingdisposed peripherally thereabout a recess or groove 22 which receives aflange formed in a pipe to which the plug will be affixed (see FIG. 6).Groove 22 comprises walls 23 and 24 which may be formed by a bifurcationformed in body 21 terminating in walls 23 and 24 and which are integralwith body 21. Groove 22 preferably extends about the full circumferenceof plug 20 thus walls 23 and 24 are co-extensive therewith. The plug ispreferably manufactured from such materials as to ensure that the wallsare elastically deformable to an extent which enables the plug to clearthe inwardly directed flange (see FIG. 6). Referring to FIG. 6 there isshown an exploded view of a plug and pipe arrangement. The plug shown inFIG. 6 corresponds to that shown in FIG. 5 and is numbered accordingly.FIG. 6 shows a typical pipe end 25 which will receive plug 20 in orderto pressure seal the pipe. The need to seal pipes in the way to bedescribed generally occurs in plumbing applications, an example of whichis where a plumber may not have completed a job and wishes totemporarily seal a pressurised fluid pipe. When installing water pipes,a plumber may terminate a pipe emanating from a wall or like structureby crimping the end of the pipe followed by welding in order to effect atemporary seal. When the plumbing work is to be re-commenced the plumbermust cut the crimped portion from the end of the pipe in order toinstall the finished fitting on the end of the pipe. This methodology istime consuming and requires oxy acetylene equipment which is costly andinconvenient. The plug according to the present invention eliminates theneed for use of the oxy acetylene equipment and also precludes the needfor crimping.

According to the sealing arrangement shown in FIG. 6, the pipe end to besealed may be cut with a roller cutter providing a finish on the end ofthe pipe which receives and retains the plug in addition to frictionalretention between the plug and the inner wall of the pipe. Pipe end 25shown in FIG. 6 includes a flange 27 disposed radially inwards which isformed consistently around the inner circumference of the pipe and formsa shoulder which engages plug 20.

The engagement takes place in the following manner. After preparation ofthe pipe end which essentially involves cutting with a roller cuttersuch that internal shoulder or flange 27 is created by use of a cuttingwheel or the like, the plumber inserts plug 20 into opening 29 in thedirection of arrow 28. Fitting takes place by simply pressing the plug20 against flange 27 which results in deformation of wall 24 so thatflange 27 locates in groove or recess 22 opposing groove bottom 22 a.Selection of the material used for the plug is important as insertionrelies on the ability of the plug material to resiliently deform inresponse to pressing against flange 27. Whilst it is preferable thatflange 27 be formed evenly around the periphery of opening 29 of pipeend 25, the plug will still be retained in position even where theflange is inconsistently formed around the pipe's circumference. Ifcutting of the pipe end is effected by a roller cutter, it ispredictable that the so formed flange will be consistent throughout thecircumference of the pipe. When plug 20 is in engagement with pipe end25, wall 24 impinges on inner surface 26 of pipe end 25 thereby creatinga form of frictional engagement assisting the ability of the plug toresist pressures exerted by the fluid in the pipe. Wall 23 sits externalof the pipe and provides a shoulder 23 a (see FIG. 7) which preventsunwanted insertion of plug 20 inside pipe 25 beyond flange 27. Thisarrangement removes the reliance of frictional engagement between theplug and the wall to provide the seal. One advantage of the arrangementdescribed is that the pipe is not damaged from mechanically appliedpressures and the flange created by the cutting wheel allows adequateresistance against pressure blow out. Suitable materials for manufactureof the plug would include (neoprene rubber). According to theembodiments shown in FIGS. 5 and 6, plug 20 is adapted with a fingergrippable formation extending from the plug which enables the user toeasily remove the plug from pipe end 25 or break the seal created.

Referring to FIG. 7 there is shown a long sectional view of a plugsimilar to that described in FIGS. 5 and 6 (absent finger grippableformation 30 ) inserted in a pipe. The arrangement of FIG. 7 has beenassigned numbers which correspond to the numbering of FIG. 6. From thelong sectional view shown in FIG. 7 it can be seen that flange 27comprises a return portion integral with pipe end 25 formed by a cuttingwheel. Flange 27 is formed by a burr about the end of the pipe as aconsequence of cutting.

FIG. 8 shows the arrangement of FIG. 7 with plug 20 removed from pipeend 25. Numbering used in FIG. 8 corresponds to that used in FIG. 7 forlike integers. As shown in FIG. 8, plug 20 is removed from the pipe end25 by means of finger grippable formation 30. Plug 20 is reusable withthe life of the seal depending upon the number of times it is used andthe material forming the seal.

Referring to FIG. 9 there is shown an alternative embodiment of theinvention. FIG. 9 shows a modified bottle plug 40 inserted in pipe end41. The bottle stopper includes a shoulder region 40 a which in useabuts flange 42 in order to resist unwanted blowing out. With thisarrangement an opening is formed in the modified bottle stopper andincludes threaded end 44 to which can be attached an apparatus to enabletesting of pressures in the pipe when the seal is in position. Handle 43facilitates sealing and release of plug 40.

It is envisaged that with the arrangements described above, a pipehaving a pressure of 500-800 kilopascals (72 psi to 120 psi) can betemporarily sealed with the plug arrangements described.

Referring to FIG. 10 there is shown an alternative arrangement forsealing an end of a pipe. The arrangement comprises plug assembly 45comprising an elastic rubber seal 46, a washer 47 and collar 48.

The assembly further comprises a nut 49 (preferably a wing nut) whichwhen rotated about threaded shaft 50 urges washer 47 against rubber seal46, causing seal 46 to laterally expand against inner surface 51 of pipe52. Pipe 52 includes annular flange 53 which is introduced into the pipeby cutting and which prevents unwanted blow out of assembly 45 by virtueof engagement between shoulder 54 and flange 53. The more nut 49 isturned, the tighter the frictional engagement between seal 46 andsurface 51 as threaded shaft 50 is drawn further away from the pipeopening.

FIG. 11 shows an alternative sealing arrangement based on the operatingprinciple employed in the arrangement of FIG. 10. Assembly 60 includes afinger grippable handle 61 connected to cord 62 which in turn isconnected to base 63. As handle 61 is pulled base 63 is urged againstrubber seal 64 which expands to seal the pipe relying partly onfrictional engagement but primarily on resistance to popping out ofassembly 60 by flange 65.

To accommodate pipes of different sizes the sealing plugs or plugassemblies may be stepped such that appropriate plug selection can bemade according to the internal diameter of the pipe.

A significant advantage of the invention in both its apparatus andmethod aspects is that the tradesman can leave the job temporarily withthe system safely under test and continue conveniently from where thejob finished and without any material wastage. The tradesman can alsorest assured that no unwanted foreign matter will enter the pipe.

It will be recognised by persons skilled in the art that numerousvariations and modifications may be made to the invention as describedherein being a sealing plug which acts against an internal flange, anddoes not rely on mechanical friction to prevent blow out withoutdepartment from the overall spirit and scope of the invention.

What is claimed is:
 1. A releasable plug for sealing an open end of afluid bearing pipe having at its open end an inwardly directed flangeformed upon cutting an end of said pipe, said plug comprising a plugbody, an annular recess formed in the body which engages said flange,and a seal which frictionally engages an inner surface of said pipethereby providing a pressure seal for said pipe, wherein upon insertionof said body into said open end, the recess engages the flange toprevent unwanted release of the plug from the pipe.
 2. A plug accordingto claim 1 wherein the plug comprises an elongated shaft including at afirst end a threaded region and at a second end a collar, a sleevesurrounding said elongated shaft and including at one end a collett andat a second end an abutment surface wherein a seal is provided betweensaid abutment surface and said collar, and wherein, the sleeve furthercomprises a recess at or near said collet which receives said flangethereby providing resistance against unwanted release of said plug fromsaid open end of said pipe.
 3. A plug according to claim 2 wherein saidthreaded region includes a nut which when rotated in a first directionupon insertion of said plug in the pipe end engages a surface of saidcollett, urging said sleeve towards said collar thereby activating saidseal such that said seal frictionally engages the inner wall of saidpipe.
 4. A plug according to claim 3 wherein said seal comprises arubber O ring.
 5. A plug according to claim 4 wherein said elongatedshaft moves relative to said sleeve upon rotation of said nut.
 6. A plugaccording to claim 5 wherein the shaft further comprises a taperedregion intermediate said threaded portion and said collar.
 7. A plugaccording to claim 6 wherein the sleeve includes a tapered region whichcorresponds to and cooperates with the tapered region on the shaft.
 8. Aplug according to claim 7 wherein, said rotation of said nut causes saidO ring to be compressed between said collar and said sleeve.
 9. A plugaccording to claim 8 further including a floating collar between the Oring and the threaded region on said elongated shaft such that uponrotation of said nut said O ring is compressed between an inner surfaceof said collar and an inner surface of said floating collar.
 10. A plugaccording to claim 9 wherein said shaft further comprises between saidtapered region and said collar a recess which receives and retains saidO ring.
 11. A plug according to claim 10 wherein the recess between thetapered region and the collar is wider than the thickness of the O ring.12. A plug according to claim 11 wherein the tapered region on the shaftbegins at the threaded portion and terminates at the recess.
 13. A plugaccording to claim 12 wherein the floating collar is able to movelongitudinally over the length of the tapered region.
 14. A plugaccording to claim 13 wherein the internal diameter of the sleeve iswider than the external diameter of the threaded portion of the shaft soas to enable the sleeve to move rotatably and longitudinally relative tosaid shaft.
 15. A plug according to claim 14 wherein the nut, shaft,floating collar and sleeve are made from a plastics material.
 16. A plugaccording to claim 15 wherein the recess on said sleeve is annular andadjacent said collett.
 17. A plug according to claim 16 wherein the plugcan be disassembled and reassembled.
 18. A plug according to claim 17wherein the collett and nut are annular.
 19. A method for releasablysealing an end of a pipe comprising: (a) cutting the end of a pipe to besealed so as to form a flange about the end of the pipe extendingradially inwards from an inner surface of the pipe; (b) taking a sealingdevice comprising a plug body, an annular recess formed in the body andwhich engages said flange, and a seal which frictionally engages aninner surface of said pipe thereby providing a pressure seal for saidpipe; and (c) inserting the device into an opening in said cut end suchthat said annular recess engages said flange thereby sealing the pipeand providing resistance against unwanted expulsion of said sealingdevice from said pipe end when said pipe contains a pressurized fluid.20. A method for sealing the end of a pipe with a removable plugcomprising: (a) taking a plug comprising a shaft having a threaded endand at an opposite end a collar, a recess including a seal, a sleeveadapted to slide along the shaft, and a nut engaging said thread; (b)inserting said plug into an end of a pipe to be sealed such that aninwardly directed flange on the pipe engages said recess formed in saidsleeve.
 21. A plug according to claim 1 wherein said plug body isdeformable and has disposed peripherally thereabout said annular recesswhich when said plug is inserted in said opening receives said flangesuch that at least one wall of said recess engages either one or bothsurfaces of the flange and/or the inner surface of the pipe to effectsealing between the plug and pipe.
 22. A plug according to claim 21wherein the plug comprises; a generally disc shaped body with the recessformed by a bifurcation in the body near the circumferential region saidbifurcation terminating in two resiliently deformable wall members suchthat the disc is generally H shaped in cross section.
 23. A plugaccording to claim 1 wherein the plug body includes; a shaft having atone end a threaded portion which receives a nut and at an opposite endan expansible rubber element, a collar engaging the end of said pipe, arecess which receives said flange; wherein when said nut is tightenedagainst said collar said rubber element expands to frictionally engagethe inner surface of the pipe said frictional engagement and engagementbetween said flange and recess preventing unwanted withdrawal of theplug from the pipe.